Course Exam Next Thursday (April 15) 7 pm Same classroom (ECJ 7.208) 2.5-hour exam Open book open notes All problem types of questions (short but comprehensive)

Objectives Finish the pumps and plumbing systems Discuss the final project

Pumps and Plumbing Very similar to fans and ducts Same principles based on fluid dynamics With some specifics

Hydronic Terms Head loss Open-loop vs. closed loop 2-pipe vs. 4-pipe

Head Loss

Table 19.1 Pipe dimensions for standard pipe

Fittings

Pumps Driving force to move air water in buildings Raise pressure and produce flow One main type Centrifugal

Pump curves NPSHR = Net Positive Suction Head Required

Finding Volumetric Flow Same procedure as for air Intersection of pump curve and system curve How can you control flow?

Changing Pump Speed

Use Multiple Pumps

Plumbing Arrangements

Example 19.7 Similar to equal friction method Calculate head loss for common pieces of system Size pipes to have equal head loss between points 2 and 3

Review for the Exam Should be able to do all calculations associated with lectures as well as HW1 Questions/problems may deal with context i.e. Explain how thermal conductivity influences fin efficiency? Holding all other parameters equal, how important is increasing the thermal conductivity

Psychrometrics and Processes (7 & 8) Know all parameters and their location/orientation on a psychrometric chart Be able to look up conversions of parameters on a psychrometric chart and with calculations Use protractor to calculate SHR and ΔW/Δh Plot processes on a chart for real buildings List what is held constant for different processes

Direct Contact (10) Describe how a cooling tower works Describe analysis procedure for direct contact devices

Cycles (3), Refrigerants (4) Describe Carnot cycle and components Understand constant variables for each component List, describe, and calculate inefficiencies Use figures, refrigerant tables and equations for different substances Contrast different refrigerants List important parameters for refrigerant selection/differentiation

Heat Exchangers (11) Differentiate types Calculate NTU, ε, c r, R, P, F, m, UA, etc. Complete broad analysis Which m is larger, which Δt is larger? Within and between heat exchangers

Heat Exchangers (11) Calculate and compare different thermal resistances Describe influence of key factors Integrate different parameters/resistances Manipulate UA equation Describe differences/parameters of relevance for wet heat exchangers

Diffusers, Duct Components (18) Select diffusers Define all terms on manufacturer data sheets Calculate pressure drop of: Straight duct Duct fittings Components (coils, VAV boxes, dampers, etc.) Differentiate fans and describe fan curves Use fan laws

Duct layout/design (18) Describe static regain method Compare to equal friction method Supply or return systems Balance the system

Project Design problem For example: Given cooling and heating load design HVAC for the building Research problem Analysis based problem. For example: Find the optimum solution for…. Developed control strategy for… Life cycle cost analysis for … ……….